For example, in analog ground-wave television broadcasting, character information and still-picture information are superimposed on the VBI (Vertical Blanking Interval) of a television broadcast signal to practice so-called teletext broadcasting for providing various kinds of character information and still-picture information in addition to video and audio data of broadcast programs.
In the digital satellite broadcasting based on BS (Broadcasting Satellite) and CS (Communication Satellite), EPG (Electronic Program Guide) data and various control data are provided in a superimposed manner in addition to video and audio data which constitute broadcast programs.
With television receiving sets and receivers having capacities of receiving analog ground-wave television broadcast and digital satellite broadcast, character broadcast information can be extracted from a received broadcast signal for display and EPG data can be extracted to form an EPG which is displayed for use in program selection.
Also, with television receiving sets and receivers for receiving broadcast signals, a guidance is displayed at the time of changing or adjusting various settings by displaying the channel number of a broadcast channel tuned in from another broadcast channel and displaying a volume level in a volume level bar at the time of volume adjustment, current time display is executed on the basis of the built-in clock circuit.
Meanwhile, television receiving sets and receivers having capabilities of receiving broadcast signals adapted to enhance ease of operation and convenience by providing users with various kinds of information conveyed by broadcast signals and executing various kinds of guidance displays as described above are high in home use and therefore play a central role among various audio visual equipment units.
Consequently, it is expected for the television receiving sets and receivers not only to realize the capabilities of providing users with the information provided from the outside and the capabilities of displaying guidance for example to enhance ease of operation and convenience in viewing but also to enhance user friendliness and entertainment.
It is therefore an object of the present invention to provide an image forming apparatus and an image forming method for realizing the enhancement in user-friendliness, entertainment, and convenience in viewing broadcast programs.